9 Jul 2015

Matte B et al. J Neuropsychiatry Clin Neurosci 2015; 27: 228-236.

In 2010, changes to the Diagnostic and Statistical Manual of Mental Disorders (DSM) criteria for the diagnosis of ADHD were proposed by the ‘American Psychiatric Association ADHD and Disruptive Behavior Disorder Work Group’ during development of the Fifth Edition (DSM-5TM) that was subsequently launched in 2013. These changes included: the addition of 4 impulsivity symptoms, and a reduction in the number of symptoms required for assigning a diagnosis of ADHD in adults (from 6 to 4). However, these two proposed changes, assessed in 133 adults in Brazil, were considered not to sufficiently improve ADHD diagnosis.

This case control study included 68 adults with ADHD who attended an ADHD outpatient programme in Brazil (July–December 2011) and 65 adults without ADHD. For each individual, DSM-5TM ADHD criteria information was collated during interviews with psychiatrists, and symptoms were rated as present/absent according to the working group proposal. To evaluate the stability of the criteria over time, DSM-5TM ADHD criteria were re-evaluated in 18 individuals with ADHD 15 days after the first interview by the same investigator.

Key results indicated that the test–retest reliability for the diagnosis of ADHD was 100%. However, whilst all but three attention symptoms had moderate test–retest reliability (kappa coefficients >0.45; p<0.05), 3 of the 4 proposed additional impulsivity symptoms failed to reach statistical significance for test–retest reliability. Furthermore, a lower threshold than was used in the previous DSM-IV for the number of symptoms required to diagnose ADHD was found to be the best cut-off for capturing clinical impairment (5 of 9 inattentive symptoms, 3 of 9 hyperactivity/impulsivity symptoms, and not using the 4 proposed additional impulsivity items).

Researchers concluded that the proposed additional 4 impulsivity symptoms did not improve ADHD diagnosis sufficiently to warrant the potential negative consequences of changing ADHD diagnostic criteria (for example, difficulty in interpreting data from prior classification systems). However, the study reinforced that a lower cut-off for the number of inattentive and/or hyperactive/impulsive symptoms might be more adequate for adult patients. The researchers recommend that these findings are extrapolated with caution to adults with ADHD from non-clinical populations and different cultural backgrounds.